(a) Field of the Invention
The present invention relates to a plug-in hybrid vehicle, and more particularly to a system for recharging a plug-in hybrid vehicle. In particular, the present system controls pre-recharge of a DC link in a plug-in hybrid vehicle provided with two motors when a high voltage battery is recharged with an exterior AC electricity.
(b) Description of the Related Art
In order to meet tightened exhaust gas regulations on vehicles and to provide enhancement of fuel consumption, hybrid vehicles have been developed.
A hybrid vehicle generates electricity using regenerative braking in which a motor rotates inversely during deceleration and recharges a battery. The hybrid vehicle can also reduce fuel consumption and exhaust gas through ISG (Idle Stop and Go) control. In particular, using ISG, the engine is stopped when the vehicle stops, and the engine is restarted by using the motor when the vehicle begins to run.
In addition, a plug-in recharging method may be applied to the hybrid vehicle. According to the plug-in recharging method, the battery is recharged by using an exterior commercial electricity source.
In order to apply the plug-in recharging method, an on-board charger may be provided to suitably rectify the commercial electricity and slowly recharge the battery. However, such on-board chargers are very expensive and heavy, and thus manufacturing costs of the hybrid vehicle increase and fuel efficiency may be deteriorated. In particular, the cost of an on-board charger is about ten times as expensive as that of an inverter which provides the same output. Thus, manufacturing costs of hybrid vehicles increase excessively and price competitiveness is greatly deteriorated. Further, since the charger is generally mounted in a limited space, it is very difficult to manufacture the charger as a package. In addition, it is desirable to provide a high-speed recharging device that recharges the battery in a short time. In attempts to accomplish this, the commercial electricity source can be connected to a high-speed recharging device. However, the high-speed recharging device must communicate with a high-speed battery controller in real time so as to prevent overcharge of the battery and protect the battery. For this purpose, the high-speed recharging device generally is provided with an additional communication channel. However, in a case that the communication channel of an exterior system is connected to controllers in the hybrid vehicle, it is difficult to provide a reliable controller.
Further, since a voltage of a DC link is 0V, in situations when the battery is recharged through the plug-in recharging method, the commercial electricity source of high voltage is connected to an inverter. As a result, initial inrush current may occur to thereby damage electric switching elements of the inverter.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.